Development Of Teaching System Of Grinding Manipulator

In the field of grinding and polishing,industrial robots are gradually replacing traditional manpower.However,the diversification of the processing workpieces,the complexity of the workpiece surface,and the processing quality requirements make the teaching tasks tedious and requires a high level of technical skills for the operators.For this purpose,a six-degree-of-freedom teaching arm system has been developed to manually teach the workpiece by manually dragging the workpiece or polishing wheel held at the end of the teaching arm.During this process,the teaching arm at each time is recorded.Each joint angle can be reproduced and processed by an industrial robot by a certain conversion.First,design the teaching arm body structure.In order to realize the teaching system imitating the manual operation,according to the human bionics,the teaching arm is modeled on the human arm.Therefore,the overall structure of the teaching arm includes four parts like a shoulder,a big arm,a small arm and a hand of the human arm.Since each adjacent part of the human body arm includes a rotational and relative twisting motion,the joints of the various parts of the teaching arm are respectively designed for the rotary joint and the torsion joint.And from the perspective of easy dragging and light weight,the teaching arm is optimized for material selection and structure.Secondly,according to the design of the teaching arm structure,the positive kinematics model of the teaching system is established,and the relationship between the angle of each joint of the teaching arm and its end position and posture is determined.Considering the processing of workpieces in the same position in the world coordinate system by the industrial robot and the teaching arm in different base coordinate systems,the position matrix of the teaching arm base coordinate system to the industrial robot base coordinate system is determined.The inverse kinematics model was established for the reconstruction system.The problem ofmulti-solutions of manipulators in different configurations was considered.The inverse solution values of the manipulator's joint motors were obtained by combining the geometric method and the analytical method.The appropriate solution set was chosen according to the actual work situation.Again,the hardware platform and software interaction interface of the data acquisition system are designed according to the recording conditions required by the teaching system.Six rotary encoders were selected as the acquisition devices for each joint signal,and real-time synchronous data acquisition was realized through the FPGA development board.From the perspective of easy observation by the operator,the important information in the teaching process is displayed in the interactive interface window,and the collected data can be written into the upper computer for further calculation and processing.Next,use the ADAMS software to set up a virtual prototype model for the teaching-reproducing system consisting of teaching arm and manipulator,and carry out kinematics simulation.The acquired data was used to verify the correctness of forward and inverse kinematics equations,and to detect the parametric performance of the interventional arm during the movement of the teaching arm and manipulator,and the end and joint speed.Finally,a teaching-reproducing experimental platform is set up to teach the simple trajectory and verify the teaching trajectory reproduction effect by the industrial robot.